Table 1.

PRESERVE score parameters [9]

Parameter		Points
Age (years)	<45	0
	45-55	2
	>55	3
Body mass index	>30 kg/m2	−2
Immunocompromiseda		2
Mechanical ventilation	>6 days	1
SOFA	>12	1
No prone positioning before ECMO		1
PEEP	<10 cmH2O	1
Peak inspiratory pressureb	>35 cmH2O	1

^aDefined as hematological malignancy, solid tumor, solid organ transplantation, high-dose or long-term corticosteroid and/or immunosuppressant use or HIV infection. ^bOr plateau pressure >30 cmH₂O = 1 point as proposed by Schmidt and colleagues [9]. ECMO, extracorporeal membrane oxygenation; PEEP, positive end-expiratory pressure; PRESERVE, Predicting Death for Severe ARDS on VV-ECMO; SOFA sepsis-related organ failure assessment.